Using New Space-Saving Photo Files

Q.I have a new iPhone 8 with iOS 11. I thought the new system was supposed to save photos in that new H.E.I.F. format to save space, but when I send pictures as mail attachments, they show up as JPG files. What gives?

A. Apple’s recent iOS 11 update does support the new High Efficiency Image File Format for photos; the company uses the file suffix .HEIC for images using the new standard. Additionally, the iOS 11 system uses the newer High Efficiency Video Codec (H.E.V.C.) for videos captured with compatible iPhones and other iOS devices. To be able to use the new formats, you need to be running iOS 11 on an iPhone 7 or later, or on one of the latest iPad Pro models. Macs running the new macOS High Sierra operating system are also compatible.

Among other advantages, the new formats store higher-quality images in less space. An H.E.I.F. photo can be about half the file size of a picture saved in the JPG format, and this allows you to store more photos on your phone. Because not every hardware and software maker out there immediately supports new formats, Apple has added tools to help iOS 11 users share and edit their photos and videos without hassle.

For example, when you send a photo you have just snapped on your phone by email, the iOS 11 software quietly converts the file to a JPG so your recipient will not have any trouble opening the attachment and viewing the picture. Pictures posted to social media sites are similarly converted.

You can see files in the new formats if you import them into a Mac running macOS High Sierra, and the space those photos occupy on the drive will be smaller. Some file-sharing services like Dropbox already support the new standards, and others are likely to come along in time.

Image

You may not even realize iOS 11 is saving pictures in the new file format unless you look at the images in a compatible program, like the Photos app on macOS High Sierra.CreditThe New York Times

If you care more about compatibility than drive space and do not want to take any chances, you can change the default format for your pictures. On the iPhone’s home screen, tap the Settings icon, then Camera and select Formats. In the Camera Capture area, choose High Efficiency to use the H.E.I.F. and H.E.V.C. formats for your photos and videos — or go with Most Compatible to use the older JPG photo and H.264 video formats. Apple notes that if you opt for Most Compatible, you will not be able to record video at the 4K 60 frames per second setting, or at the 1080p 240 f.p.s. setting.

Personal Tech invites questions about computer-based technology to techtip@nytimes.com. This column will answer questions of general interest, but letters cannot be answered individually.

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